Abstract: :
Purpose: The tear film lipid layer is believed to stabilizethe tear film by preventing evaporation. We characterized lipidand protein deposited on Schirmer strips to determine compositionaldifferences associated with patients with dry eye symptoms.Methods: Schirmer strips were collected from patients with andwithout dry eye symptoms. Samples were grouped as: no dry eye,dry eye, dry eye treated with saline eye drops, dry eye treatedwith antibiotics. Attenuated Reflectance Spectroscopy (ATR)was used to characterize compositional changes on Schirmer strips.The composition of lipid extracted from Schirmer strips wasmeasured using matrix-assisted laser desorption ionization /time of flight mass spectrometry (MALDI / TOF MS). Results:Total lipid on Schirmer strips from all dry eye groups was significantlylower compared to the group without dry eye. Among the dry eyegroups, the group treated with antibiotic exhibited significantlylower lipid on Schirmer strips. The intensity of the infraredamide and CH2 stretching bands were significantly lower in ATRspectra of Schirmer strips from the dry eye groups indicatingless lipid and protein. The ratio of the intensity of the OH/CH2infrared stretching bands was significantly higher in the dryeye groups indicating that Schirmer strips from the dry eyegroups contained more protein relative to lipid. MALDI/ TOFMS data indicate that the relative amount of sphingomyelin decreaseswhile the amount of the phosphatidylcholine increases. Conclusions:The composition, total and relative amount of lipid is loweron Schirmer strips from patients with dry eye symptoms. ATRand MALDI / TOF MS analysis of Schirmer strips may be usefulfor screening patients with dry eye symptoms and provide compositionalinformation that may be useful in elucidating the etiology ofdry eye symptoms.